package com.tockm.controller;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.util.ResourceUtils;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@Slf4j
@Controller
public class DownloadController {
    /**
     * @param path     想要下载的文件的路径
     * @param response
     * @功能描述 下载文件:
     */
    @RequestMapping("/download")
    public void download(String path, HttpServletResponse response) {
        try {
            // path是指想要下载的文件的路径
            String path2 = ResourceUtils.getURL("classpath:").getPath() + "static/files/step.zip";
            String fileName = "step.zip";
            String path1 = "/opt/www/files/"+fileName;
            File file = new File(path1);

            // 获取文件名
            String filename = file.getName();
            log.info(fileName+"下载完成");
            // 获取文件后缀名
            String ext = filename.substring(filename.lastIndexOf(".") + 1).toLowerCase();
//            System.out.println("文件后缀名：" + ext);
            log.info("文件后缀名：" + ext);

            // 将文件写入输入流
            FileInputStream fileInputStream = new FileInputStream(file);
            InputStream fis = new BufferedInputStream(fileInputStream);
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();

            // 清空response
            response.reset();
            // 设置response的Header
            response.setCharacterEncoding("UTF-8");
            //Content-Disposition的作用：告知浏览器以何种方式显示响应返回的文件，用浏览器打开还是以附件的形式下载到本地保存
            //attachment表示以附件方式下载   inline表示在线打开   "Content-Disposition: inline; filename=文件名.mp3"
            // filename表示文件的默认名称，因为网络传输只支持URL编码的相关支付，因此需要将文件名URL编码后进行传输,前端收到后需要反编码才能获取到真正的名称
            response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
            // 告知浏览器文件的大小
            response.addHeader("Content-Length", "" + file.length());
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            outputStream.write(buffer);
            outputStream.flush();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

}
